The present invention relates generally to phase selection, and more specifically, to a method of determining a synchronous phase from a correlation sequence.
Communication in electronic devices such as mobile phones, laptop computers, Personal Digital Assistants (PDAs), cameras, and so forth, can be asynchronous or synchronous. In asynchronous communication, a transmitter clock and a receiver clock are independent and are not synchronized. There are various standards, such as the Third Generation Digital Baseband/Radio Frequency (3GDigRF) standard, for asynchronous communication. The 3GDigRF standard defines an efficient physical interconnection between a transmitter and a receiver, such as a Baseband Integrated Circuit (BBIC) and a Radio Frequency Integrated Circuit (RFIC) for electronic devices. The 3GDigRF standard ensures that integrated circuits (IC) complying with the standard, when correctly configured, can communicate with each other. Such communication requires acquisition of phase by selecting a phase corresponding to a correlator signal. This phase acquisition ensures synchronization before the data can be recovered from a received signal. The phase acquisition is carried out using a known sequence such as a Post Office Code Standardization Advisory Group (POCSAG) sequence, which is a basic signaling pattern with a sequence of coded binary data such as ‘1010100001001011’, which facilitates transmission in a single-batch.
The phase acquisition technique can suffer from a bias if the phases for synchronization are not resolved correctly. This can limit the duration of the packet transfer with a required Bit Error Rate (BRR). This can also limit the rate of transfer of the packet.
An existing technique carries out the synchronization by observing edge transitions and then performing the centering using the set-up and hold-time information. The technique does not address bias removal or the conflicted centering of phase selection. Thus, it would be desirable to have an accurate phase acquisition technique.